Pluralistic ignorance and measuring norms

Summary of Week 4 of Social Norms, Social Change I (Coursera – University of Pennsylvania & UNICEF)

Pluralistic ignorance

Pluralistic ignorance occurs when many people privately condemn a behaviour but wrongly believe that their peers endorse it. This can occur because the behaviour or its consequences are visible but people do not voice their disagreement, leading to a lack of transparent communication. In such cases, updating normative expectations can help to change behaviour.

A different but related situation is when people misperceive the frequency of a behaviour (e.g. prevalance of corruption or drinking). Correcting misperceptions can change descriptive norms but not social norms.

Measuring norms

To measure norms, you must check empirical expectations, normative expectations and whether there is a conditional preference.

Behaviour can be measured through monitors or self-reports. Personal normative beliefs can be measured through surveys, and it is important to distinguish between prudential and non-prudential beliefs.

If empirical and normative expectations are mutually consistent, it is PROBABLE that there is a norm, but it could also signal a moral rule. Therefore it is necessary to check whether preferences are conditional. This is done by varying empirical and normative expectations and checking whether behaviour changes, through direct hypotheticals or vignettes.

You can also measure how stable a norm is by assessing which expectation has more weight. For example, when empirical and normative expectations diverge, empirical expectations usually dominate.


Thus, through systematic measure, you can diagnose whether a behaviour is a custom, moral rule or true social norm, and whether the social norm has causal relevance.



Water treatment options

Summary of Week 2 of Introduction to Household Water Treatment and Safe Storage (Coursera – École Polytechnique Fédérale de Lausanne)

Water safety

In water treatment (and in life), the question is what level of risk is acceptable. WHO defines safe drinking water as water that presents no significant risk to health over a lifetime of consumption.

The water safety framework comprises health-based targets, water safety plans and verification. Health-based targets include performance measures in terms of log reduction values.

It is important to note that measuring water quality is not the same as water safety because water quality varies in space and time, and no E.coli does not mean no contamination. Multiple treatment barriers should be put in place to remove contaminants.

Health-based targets include performance measures in terms of log reduction values. Water quality measurement does not mean water safety because water quality is variable in space and time, and no E.coli does not mean no contamination

Water treatment options: Sedimentation and filtration

A household-level treatment process typically comprises sedimentation, filtration, disinfection and safe storage.

  • Sedimentation removes turbidity (suspended particles in water), and some pathogens. Turbidity itself has no health risks, but has impacts on subsequent treatment steps. Mechanisms include gravity settling, and coagulation and flocculation.
  • Membrane filtration works on size exclusion, electrostatic effects and biological activity.
  • Ceramic filters work on physical and electrostatic removal. It is common to brush silver onto filters, which contributes to bacteria reduction and prevents biofilm growth and clogging.
  • Biosand filtration also uses size exclusion, electrostatic effects and biological activity.

Conditional preferences and social norms

Summary of Week 3 of Social Norms, Social Change I (Coursera – University of Pennsylvania & UNICEF)

Conditional preferences

Preference is a disposition to act in a certain way. It is different to liking or endorsing something.

Conditional preferences means that a choice is dependent on empirical expectations (descriptive norms) or both empirical and normative expectations i.e. if different expectations lead to different behaviour, then people have conditional expectations. It is important to note that consistency between social expectations and behaviour does not mean that the behaviour is influenced by expectation.

Whether people have conditional preferences influences the intervention that is designed. If people have conditional preferences, the intervention should focus on changing social expectations.

Social norms

A social norm is a rule of behaviour such that people prefer to conform to the norm conditional on empirical and normative expectations. Under social norms, there are usually informal social sanctions that motivate compliance. Hence the presence of sanctions indicate that there are normative expectations. However, some people might comply without sanctions if they believe that other people’s normative expectations are legitimate.

(If empirical expectations were sufficient to motivate compliance, this would be a descriptive norm. )

Motivations for behaviour differ from community to community. Bicchieri provides a useful visual summary for diagnosing whether a behaviour is a custom/rule, descriptive norm or social norm.


Source: Bicchieri in Social Norms, Social Change I


Introduction to Household Water Treatment and Storage

Summary of Week 1 of Introduction to Household Water Treatment and Safe Storage (Coursera – École Polytechnique Fédérale de Lausanne)

There are many diseases caused by poor water, sanitation and hygiene. In particular, diarrhea is a leading cause of mortality and morbidity.

Diseases related to poor water, sanitation and hygiene can be classified according to its transmission pathways: waterborne, water-washed, water-based and water-related. This is the Bradley classification, and informs the selection of appropriate control mechanisms.

These diseases are caused by pathogens that can be described by its biological type: protozoa, bacteria, viruses and helminths. These are transmitted through pathways illustrated by the F-diagram.

Because it is impractical to measure all pathogens, faecal indicators area used. Escherichia coli (E.coli) is generally considered the most suitable, although it does not necessarily co-relate to contamination risk. A more complete picture can be obtained by also doing a sanitary inspection. Contamination can occur at the point of the water resource, delivery, collection and transport, household storage, and consumption.

Household water treatment offers the opportunity to remove contamination that occurs before consumption. Treatment processes include sedimentation (pre-treatment), filtration, boiling, UV radiation (solar disinfection) and chlorine. Each process has different levels of effectiveness and different applications.

Normative Expectations and Personal Normative Beliefs

Summary of Week 2 of Social Norms, Social Change I (Coursera – University of Pennsylvania & UNICEF)

Normative Expectations

Besides empirical expectations, the second type of social expectation is expectations of what people think we should do. It is a second-order belief that are often paired with an expectation of a positive or negative sanction (e.g. shaming). Depending on the circumstances, different people will matter to our decisions. Or, they may not matter because we do not care. For instance, normative expectations do not matter for customs, descriptive norms and moral norms.

Personal normative beliefs

Personal normative beliefs are what I think I should, or people in general, should do. Normative beliefs overlap with normative expectations that the lecturer (Bicchieri) states that while normative beliefs matter to choice, normative expectations carry more weight.

Bicchieri also brings up the measurement of attitudes in surveys. Attitudes are very wide (i.e. personal normative beliefs is a narrower category) and just measuring attitudes might not provide a clear understanding of underlying beliefs and expectations. Thus she recommends making a clearer distinction in surveys.


Interdependent and Independent Behaviour, and Empirical Expectations

Summary of Week 1 of Social Norms, Social Change I (Coursera – University of Pennsylvania & UNICEF)

Interdependent and independent behaviour

When people engage in a collective behaviour, it is important to understand whether the action is interdependent. This is because interdependent actions are influenced by what a person’s reference network – the set of individuals who matter to me when I have to make a particular decision – does or think we should do.

In contrast to an interdependent action, a custom is a pattern of behaviour that individuals prefer to conform to because it meets their needs. For example, people open defecate because it requires the least amount of work – it is not conditional on how others defecate or what other people think of you when you open defecate.

Changing customs can be difficult because the alternative behaviour may require collective action that entails introducing interdependencies. Thus, understanding the interdependence of a collective behaviour helps us decide what type of intervention offers the best chance of success.

Empirical expectations

Empirical expectations refer to situations when the expectations of what other people do guide my actions. They can be:

  • Unilateral (when others don’t have expectations of me)
    • When we want to imitate someone
    • When what others do is informative (social proof)
  • Multilateral (when others also have expectations of me)
    • To coordinate with others

Empirical expectations are important to the lecturer’s (Bicchieri) definition of descriptive norms, which she describes as a pattern of behaviour that we prefer to engage in because we believe that others follow it. (This differs from the definition from social psychology.)




Water development paths

Review of Week 6 of Water Supply and Sanitation Policy in Developing Countries Part 1: Understanding Complex Problems (University of Manchester, Coursera)

The final week considered the pathways to achieving full water supply and sanitation coverage. There are different pathways, such as water first or eliminating open defecation first, and there is no one right pathway. One approach could be to listen to what the community wants (which is my personal preference).


The lecturers then examined UK’s water and sanitation development path, with examples from London and Manchester.

Due to time constraints, I was not able to complete the final assignment. But the exercise to produce a policy memo for evaluating UNICEF’s water supply and sanitation program in Africa looked very interesting… I may just have to retake this module in future!